Motor vehicle assembly units of the type described above are known in the field in different embodiments. As such, the connection of motor vehicle fluid lines made of plastic, for example polyamide 12, by means of a connector or quick connector, respectively, is known, in which the fluid line engages in a form-locking or friction locking manner in an engagement section of the connector. The providing of a securing profile in the engaging section of the connector, for an improved securing of the fluid line, is also known. Many of the known motor vehicle assembly units have the disadvantage, however, that the fluid line is no longer sufficiently functionally reliably and effectively attached to the connector at higher pressures and/or at higher temperatures. The use of hose clamps or similar items for improving the attachment is time-consuming or costly, and is accompanied by geometric limitations. Many known motor vehicle assembly units furthermore have the disadvantage that the fluid line ends that are to be connected to the connector are relatively unprotected with respect to liquid media, in particular corrosive liquid media, for example, with respect to spray water.